Flexible decision making in dynamic environments contributions of sensory adaptation and arousal-related neuromodulation Kara D McGaughey

Format:

Book

Thesis/Dissertation

Author/Creator:

McGaughey, Kara D., author.

Contributor:

University of Pennsylvania. Neuroscience., degree granting institution.

Language:

English

Subjects (All):

Neurosciences.

Bioengineering.

Cognitive psychology.

0317.

0202.

0633.

Local Subjects:

Neurosciences.

Bioengineering.

Cognitive psychology.

0317.

0202.

0633.

Genre:

Academic theses

Physical Description:

1 online resource (118 pages)

Contained In:

Dissertations Abstracts International 87-12B

Place of Publication:

Ann Arbor : ProQuest Dissertations and Theses, 2026

Language Note:

English

Summary:

Effective decision making in dynamic environments requires flexible evidence accumulation. Although models often express this flexibility as an adaptive "leak" parameter governing accumulator dynamics, its implementation in the brain may involve adaptive mechanisms operating at multiple stages of the decision process. For instance, sensory adaptation could modulate evidence encoding through stimulus-history-dependent changes in sensory responses, while arousal-related neuromodulation could adjust evidence encoding and/or accumulation based on learned expectations about environmental stability. We tested these possibilities by recording single-unit activity in the middle temporal area (MT) of non-human primates and measuring pupil-linked arousal while they performed a modified random-dot motion direction-discrimination task in which an adapting stimulus with varied temporal stability (id est, one vs. five switches in dot-motion direction) preceded a behaviorally relevant test stimulus. We found that monkeys flexibly adjusted their decision-making behavior in a manner consistent with an adaptive leak that depended on temporal context stability, accumulating less evidence over time when the test stimulus was preceded by a more unstable adapting context. Temporal context stability also systematically affected MT neural activity, with reduced activity and motion-direction discriminability during the behaviorally relevant test stimulus in the high relative to low switch-frequency condition. These changes in MT neural activity emerged over the course of each trial, consistent with stimulus-specific sensory adaptation. Adaptation-driven changes in MT evidence encoding were behaviorally relevant, but not fully prescriptive of context-dependent adjustments in evidence accumulation, implying that additional mechanisms likely contribute to this behavioral flexibility. Consistent with this idea, fluctuations in task-evoked pupil size, an index of arousal-related neuromodulation, were systematically related to both temporal context stability and to context-dependent differences in evidence-accumulation behavior. Notably, context-dependent modulations of pupil size were not systematically related to context-dependent modulations of MT neural activity or discriminability, suggesting that sensory adaptation and arousal-related neuromodulation both contribute to behavior, but may do so through distinct mechanisms at different processing stages. Additionally, preliminary work in human subjects performing the same task revealed similar patterns of context-dependent behavior and pupil-behavior relationships, though the small sample size limited statistical power and further work is needed. Collectively, these findings identify complementary roles for stimulus-specific sensory adaptation and arousal-related neuromodulation in shaping flexible, context-dependent evidence accumulation

Notes:

Source: Dissertations Abstracts International, Volume: 87-12, Section: B.

Advisors: Gold, Joshua I. Committee members: Burge, Johannes; Schapiro, Anna C.; Cohen, Yale E.; Donner, Tobias H.

Ph.D. University of Pennsylvania 2026

Vendor supplied data

Local Notes:

School code: 0175

ISBN:

9798247979869

Access Restriction:

Restricted for use by site license